1. Field of the Invention
The present invention relates to a reciprocating type compressor and more particularly, to a compressor having a discharge pulsation reducing structure for reducing pulsation when discharging refrigerant.
2. Description of the Prior Art
Generally, compressors are widely used for compressing refrigerant in refrigerating apparatus, such as refrigerators.
As shown in FIG. 1, general reciprocating type compressors comprise a casing 10 having an upper shell 11 and a lower shell 12, a compressing part composed of components, which are placed at a lower part of inside of the case 10 for compressing refrigerant, and a motoring part 20 for driving the compressing part.
The motoring part includes a stator 21, a rotator 22 that is rotated by the electronic interaction with the stator 21, and a crankshaft 23 press-fit in the center of the rotator 22.
The compressing part includes a cylinder block 30 installed at the lower part of the inside of the case 10, a connecting rod 40 eccentrically connected to a lower part of the crankshaft 23, a piston 50 connected to a front end of the connecting rod 40, reciprocating linearly inside of a compressive chamber 31 formed in the cylinder block 30, and a cylinder head 60 disposed at the front (32; refer to FIG. 2) of the cylinder block 30 to seal the compressive chamber 31. In the cylinder head 60, a refrigerant suction chamber 61 and a refrigerant discharge chamber 62 are separately formed up and down respectively. A valve assembly 70 is installed between the cylinder head 60 and the front 32 of the cylinder block 30. The valve assembly 70 controls flow of the refrigerant in the refrigerant suction chamber 61, the refrigerant discharge chamber 62, and the compressive chamber 31.
Meanwhile, a suction muffler 80 connected to the refrigerant suction chamber 61 is disposed at an upper of the cylinder head 60. A refrigerant suction pipe 81 that draws refrigerant from an evaporator (not shown) is connected to the suction muffler 80.
As shown in FIGS. 2 and 3, a discharge muffler 33 protrudes from the bottom of the cylinder block 30, and the discharge muffler 33 is sealed by a muffler cover 34. A refrigerant discharge pipe 35, a channel for supplying refrigerant to a condenser (not shown), is connected to the muffler cover 34. A refrigerant discharge hole 32a is formed in the front 32 of the cylinder block 30, and the refrigerant discharge hole 32a is connected to the discharge muffler 33 by a refrigerant passage 37.
On the other hand, the valve assembly 70 comprises a suction valve plate 71 having a suction valve 71a formed thereon, and a discharge valve plate 72 having a discharge valve 72a formed thereon. The suction valve 71a controls flow of refrigerant between the compressive chamber 31 and the refrigerant suction chamber 61 of the cylinder head 60. The discharge valve 72a controls flow of refrigerant between the compressive chamber 31 and the refrigerant discharge chamber 62 of the cylinder head 60.
In the above construction, a process of discharge of refrigerant drawn into the compressor after being compressed by the piston 50 is as follows.
Firstly, if the piston 50 retreats to a bottom dead point (to the left direction in FIG. 1) inside of the compressive chamber 31 by rotation of the crankshaft 23, refrigerant of low temperature and low pressure is drawn from an evaporator into the suction pipe 81. The refrigerant is drawn into the compressive chamber 31 after passing the suction muffler 80 and the refrigerant suction chamber 61 of the cylinder head 60, sequentially. Then, as the piston 50 progresses to a top dead point (to the right direction in FIG. 1) in the compressive chamber 31 rotation of the crankshaft 23, refrigerant is compressed to high temperature and high pressure by the refrigerant. Such compressed refrigerant is drawn into the discharge muffler 33 via the refrigerant discharge hole 32a of the front plate 32 of the cylinder block 30 and the refrigerant passage 37, after staying in the refrigerant discharge chamber 62 of the cylinder head 60 for a determined time. After that, the high temperature and high pressure refrigerant is discharged to a condenser (not shown) via the refrigerant discharge pipe 35 connected to the muffler cover 34.
However, the reciprocating compressor as described above has a problem of generating discharge pulsation since refrigerant cannot be discharged consecutively because the piston 50 discharges refrigerant after drawing and compressing by doing reciprocal action in the compressive chamber 31. This discharge pulsation of refrigerant becomes a main reason of vibration and noise of the compressor. Especially, the noise of the compressor that is generated in low frequency band about 120 Hzxcx9c500 Hz of natural frequency of other components of a refrigerating apparatus increases the noise of the entire refrigerating apparatus and vibration due to resonance with other components of the refrigerating apparatus.
Increasing the flow resistance of the discharged refrigerant can reduce this kind of discharge pulsation of refrigerant. In other words, discharge pulsation of refrigerant would be reduced by decreasing the cross-sectional area of the refrigerant passage 37 between the discharge muffler 33 and the refrigerant discharge chamber 62 of the cylinder head 60 or by lengthening the length of the refrigerant passage 37. Yet, if the cross-sectional area of the refrigerant passage 37 becomes too small, the efficiency of the compressor would be reduced since refrigerant cannot flow smoothly between the refrigerant discharge chamber 62 and the discharge muffler 33. In addition, there is a limitation to the possible length of the refrigerant passage 37, since the refrigerant passage 37 is passed through the cylinder block 30.
The present invention has been made to overcome the above-mentioned problems of the related art. Accordingly, an object of the present invention is to provide a compressor that can reduce discharge pulsation without decreasing the compressing efficiency by improving refrigerant discharge structure.
The above object is accomplished by a compressor including a cylinder block having a refrigerant discharge chamber installed in a cylinder head; a first discharge muffler that is installed at a lower part of the cylinder block; a second discharge muffler installed at a lower part of the cylinder block and whereto a refrigerant discharge pipe is connected; a refrigerant passage having a greater cross-sectional area of refrigerant suction part than that of refrigerant discharge part, and the refrigerant passage connects the refrigerant discharge chamber and the first discharge muffler; a connector that connects the first discharge muffler and the second discharge muffler. Each of the cross-sectional diameter of the refrigerant suction part and an inner diameter of the connector has different sizes with predetermined proportions.
It is preferable that the cross-sectional diameter of the refrigerant suction part and the inner diameter of the connector have predetermined proportions to meet the following conditional expression.
[Conditional expression]
("PHgr"1):("PHgr"2)=2.0xc3x976.4:1.78xc3x972.6 
Moreover, the relative proportion between the diameter ("PHgr"1) and the inner diameter ("PHgr"2) of the compressor is 6.4:1.78.
It is advisable that the relative proportion between the diameter ("PHgr"1) and the inner diameter ("PHgr"2) is 6.4:2.16.
It is also advisable that the relative proportion between the diameter ("PHgr"1) the inner diameter ("PHgr"2) is 6.0:1.78.
In addition, it is preferable that the proportion between the diameter ("PHgr"1) and the inner diameter ("PHgr"2) is 6.0:2.16.
In addition to the above proportions, it is preferable that the relative proportion between the diameter ("PHgr"1) and the inner diameter ("PHgr"2) is 6.0:2.6.
Lastly, it is advisable that the length of the refrigerant suction part (L2) to the entire length of the refrigerant passage (L1) is constructed with a predetermined proportion to meet the following conditional expression.
[Conditional Expression]
(L1):(L2)=45: a range between 15 to 30
Moreover, it is preferable that the relative proportion between the length (L1) and the length (L2) is 3:1.
In addition, it is advisable that the relative proportion between the length (L1) and the length (L2) is 3:2.